What Is The Oldest Aquarium Fish In The World?
The average lifespan of fish can vary considerably depending on their size, the quality of the water they swim in and the quality and amount of aquarium fish food they eat.
Whilst fish tend to live between 5 and 100 years, most fish tend to be on the lower side of this lifespan list, although habitat conditions can cause a fish’s lifespan to vary greatly, as does the size and whether a fish lays eggs or gives birth to live young.
For example, goldfish can live up to 25 years if taken care of but have a reputation for not being long-lasting due to often being poorly taken care of, whilst bettas tend to have an average lifespan of less than two years.
The world’s oldest fish currently living in an aquarium is almost four times as old as the maximum lifespan of a goldfish, was in its current home before the outbreak of the Second World War, and closely resembles the missing link between fish and their prehistoric ancestors.
Methuselah, named after the biblical figure who lived for 969 years, is a lungfish currently believed to be around 90 years old; She has been in her current home for 84 years but biologists at the time did not know how old she was at the time.
She has taken the title of being the oldest fish in an aquarium after Granddad, another lungfish in his mid-90s was put down in 2017 due to failing health and refusing food.
According to the biologists at the California Academy of Sciences who have taken care of Methuselah, she acts like an ‘underwater puppy’ more than a fish, in the sense that she is mellow, gentle but will suddenly flee if spooked.
She also apparently likes belly rubs and fresh figs, although due to her age she has become increasingly picky with her food. According to one of her carers, she prefers prawns in the winter and the tiny fish smelt in summer.
She could even be trained and was more approachable than most types of fish species, with many of the biologists loving working with her.
However, whilst she is the oldest fish in an aquarium, the oldest fish in the world could be three times her age.
A Three-Century Old Fish
The oldest living fish and oldest living vertebrate species of them all is the Greenland shark, with the lifespan of the species varying between 272 and 512 years of age, which means that the oldest of the sharks found were alive long before William Shakespeare was born.
Native to the North Atlantic and Arctic Oceans, they can grow up to 7m in length and weigh up to 1200kg, with this huge size and their slow metabolism aided by the cold deep waters they call home credited for their long lives, as they slowly travel through the ocean hunting sleeping prey.
As well as this, its tissues contain a natural antifreeze chemical called trimethylamine N-oxide, which is toxic to eat, dissuading other predators from eating them and contributing to their longer-than-usual lives.